Marriage without a state license - recommendations for officiants?

[Jethro]

I wouldn't have did a mere certificate.
I would have drafted a private marriage contract.

You, your wife, and several witnesses can sign the document.
The document can also be filed with the county recorder if you choose.

You can do that, too, though I wouldn't put the contract on public record. That's nobody else's business. A certificate showing that there was an exchange of vows on X date with the bride, groom and all the witnesses' signatures should be sufficient evidence a wedding took place for public notice purposes.